DISCLAIMER: THESE INSTRUCTIONS ARE PROVIDED FREE OF CHARGE. USE THEM AT YOUR OWN RISK. YOU MUST DECIDE IF THIS SERVICE/PORT IS REQUIRED FOR YOUR SPECIFIC ENVIRONMENT. IF YOUR SYSTEM REQUIRES THIS SERVICE/PORT, THEN DON'T TURN IT OFF! WE DO NOT PROVIDE SUPPORT FOR THE "How To" PAGES. PLEASE CONSULT WITH YOUR SYSTEM ADMINISTRATOR OR YOUR OPERATING SYSTEM VENDOR FOR MORE INFORMATION ABOUT THIS PORT/SERVICE.

 

To close port 139 (netbios-nbsession):

Windows 98
Windows NT 4.0
Windows 2000
Linux Redhat 6.2
Windows XP


Windows 98 - follow these steps:

  1. Click on "Start" → "Settings" → "Control Panel"
  2. Double click on "Network"
  3. Select the "Configuration" tab
  4. Scroll down network component list and find and select item starting with "TCP/IP -> ..."
  5. Then select "Properties"
  6. Select the "Bindings" tab
  7. Deselect each option then click "Ok"
     
  8. Ignore windows warning message "have not selected any drivers to bind with." Click "No"
  9. Repeat steps 4-8 until each instance of "TCP/IP -> ..." is changed
  10. Restart computer
    (ports 137 & 138 will also be closed)


Windows NT 4.0 - follow these steps:

  1. Click on "Start" → "Settings" → "Control Panel"
  2. Double click on "Network"
  3. Select the "Bindings" tab
  4. Scroll down "Show bindings for:" list and select "all protocols"
  5. Double click on "WINS Client(TCP/IP)"
  6. Highlight your network adapter
  7. Click on "Disable"
    (ports 137 & 138 will also be closed)


Windows 2000 - follow these steps:

  1. Click on "Start" → "Settings" → "Network and Dial-up Connections"
  2. Double click on "Local Area Network"
  3. Click on "Properties"
  4. Highlight "Internet Protocol(TCP/IP)"
  5. Click on "Properties"
  6. Click on "Advanced"
  7. Select the "WINS" tab
  8. Select "Disable Netbios over TCP/IP"
  9. Click "Ok"
    (ports 137 & 138 will also be closed)


Windows XP - follow these steps:

  1. Click on "Start" → "Control Panel"
  2. Double click "Network connections"
  3. Click on "Properties"
  4. Double click Internet Protocol (TCP/IP)
  5. Click "Advanced"
  6. Click on "WINS"
  7. Click "Disable netbios over TCP/IP"
  8. Click "Ok" on all of the windows
     


Linux Redhat 6.2

To Permanently disable:

  1. cd /etc/rc.d/init.d/
  2. smb stop
  3. mv smb no.smb
    (ports 137 & 138 will also be closed)

To temporarily stop service:

  1. cd /etc/rc.d/init.d/
  2. smb stop
    (ports 137 & 138 will also be closed)

For additional information go to Beckman Institute

*Note: Some users may wish to install a personal firewall instead of disabling port 139*

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